First of all, it is not blazing fast. Probably caused by the latency (as mentioned in my previous post). It is not slow, it is just ok('ish).
Second, and way more important, it runs APEX 5.0.4! So whatever Oracle advertises about "Cloud first" ... it doesn't seem to apply to APEX (or APEX on EECS). So this fact alone makes this environment useless for demo, development and presentation purposes at this moment. I heard through the grapevine that 5.1 will be available from April 25 - but that's still a month away. And that rumour could be false.
Third, because you don't have access to a SYS account, you can't install something like APEX-SERT. Maybe the install scripts can be adapted for the PDB_ADMIN account - I haven't looked into that yet.
Four : As mentioned in an earlier post, within an EECS PDB instance you get one and only one APEX Workspace. You can't add one (nor delete). You can create as much schema's as you wish, but you have to assign them all to that same Workspace. Thus if you need more Workspaces, you either buy multiple EECS instances or look into another - more expensive - Database Cloud offering.
Five : The default Authentication Scheme is the new "Oracle Cloud Identity Management" scheme. If you have admin rights for the Service you can add users in that layer. If you would like to use "APEX Users" as an Authentication Scheme, you need admin rights as well to create those users. Or create your own scheme if you like that better.
And finally, when you buy an EECS, you get a Customer Support (CSI) number. You should be able to use this number to access My Oracle Support (MOS) to get information, ask questions etc. But the first few weeks that number was not recognised by MOS. But as I tried it again today, it seems to "know" the number and registration is in progress.
Reading the points above and the previous post, you might think EECS is not that good. But that all depends on what you expect to get for your money. Compared with other Oracle Cloud products, EECS is rather cheap. At some points it could do better, but especially when the service is upgraded to APEX 5.1, I will use it more for demo / development and presentations. Multiple Workspaces would be second on my wish list.
And also Oracle announced a free APEX development environment a while ago - comparable to apex.oracle.com, but with that major difference that you are officially allowed to develop applications in that new environment (apex.oracle.com is targeted as a playground - despite all the development that is probably happening there....).